Shape information of a target part of an object is one of the important information to diagnose the stage of progression of the lesion. Here, the shape information of the target part indicates the shape and the size of the target part.
In medical image diagnostic apparatuses, such as an ultrasonic diagnostic apparatus, an X-ray image diagnostic apparatus, an X-ray CT apparatus, and a magnetic resonance imaging apparatus, the shape information of the target part of the object can be measured non-invasively. The shape information of the measured target part is displayed as a medical image on a display device.
Moreover, in the medical image diagnostic apparatuses, there is a demand from an examiner that the examiner wants to measure the shape information of the target part of the object more accurately.
Therefore, PTL 1 and PTL 2 have been proposed as one image processing method to meet the demand. The image processing method disclosed in PTL 1 is performed in each of the following steps.
In the first step, an initial contour generation unit generates contour points of a plurality of initial contours of a target part.
In the second step, the examiner designates candidate points of the contours of the target part in the image.
In the third step, an initial contour selection unit selects actual contour points from the contour points of the plurality of initial contours at the positions closer to the target part.
In the fourth step, the initial contour selection unit extracts the contour of a target in the image by changing the shape of the selected initial contour such that the sum of internal energy showing the contour shape, image energy showing the characteristics of the image, and external energy given when necessary are minimized.
Moreover, in the image processing method disclosed in PTL 2, standard shape data of the boundary of the myocardium/heart chamber in the atrium or the ventricle, which has the image data collection conditions (for example, an ultrasonic scanning method, a scanning direction, or a scanned cross section for the organ to be diagnosed (heart)) as a parameter, is stored in advance, and preferable standard shape data is read on the basis of the image data collection conditions added to the image data and also the contour data is generated on the basis of the positional information of the amount of features (two points of an annulus portion and one point of apical portion) of the myocardium set by an input unit.